JP5619875B2 - Expandable bone implant - Google Patents

Description

  This application claims the benefit of US Provisional Application No. 61 / 176,517, filed May 8, 2009, the disclosure of which is hereby incorporated by reference as if set forth in its entirety. Incorporated herein.

  Vertebral compression fractures ("VCF") represent common spinal injury and can be a long-term disability. Generally, VCF involves the collapse of one or more vertebral bodies in the spine. VCF usually occurs in the lower vertebra of the thoracic vertebra or the upper vertebra of the lumbar vertebra. VCF generally involves a fracture of the anterior portion of the affected vertebral body. VCFs can cause normal alignment of vertebral bodies and deformities of the vertebral body in affected areas of the spine, such as lordosis. VCF and / or associated spinal deformities can occur, for example, due to metastatic disease or trauma of the spine, or can be associated with osteoporosis. Until recently, there were limited ways in which physicians could treat VCF and related deformities.

  In recent years, minimally invasive surgical procedures for treating VCF have been developed. These procedures typically require the use of a cannula or other access tool that is usually inserted through the pedicle into the posterior part of the subject vertebral body.

  In such an operation, a cannula or bone needle is penetrated into the soft tissue on the patient's back. After proper placement, a small amount of polymethylmethacrylate (PMMA) or other orthopedic bone cement is pushed through the needle into the subject's vertebral body. This approach may be effective in reducing or eliminating fracture pain, preventing further collapse, and restoring patient mobility. However, this approach usually does not reduce the fractured spine deformity because it does not reduce the fractured bone to its original size and / or shape.

  Other treatments for VCF are generally two phases: (1) reduction or restoration of the original height of the vertebral body, and consequent correction of lordosis of the spine, and (2) fracture Or with an increase or addition of material to support or strengthen the collapsed vertebral body.

  One such treatment involves inserting a catheter having an expandable member through the cannula into the internal volume of the fractured vertebral body. The internal volume here has relatively soft cancellous bone surrounded by broken cortical bone therein. The expandable member is expanded within the internal volume to restore the vertebral body to its original height. When the expandable member is removed from the internal volume, it leaves space in the vertebral body. PMMA or other bone filler is injected into the space via a cannula to stabilize the vertebral body. The cannula is then removed and the cement hardens, strengthening, filling or fixing the vertebral body.

  Another approach to treating VCF involves inserting an expandable mesh graft bladder or containment device into the subject's vertebral body. The graft bladder, after being inflated using PMMA or an allograft product, remains inside the vertebral body, limiting the surgical loss of reduced endplate height.

  A safe and effective device and method for assisting and / or augmenting fractures or otherwise damaged vertebral bodies and other bones, preferably vertebral bodies that will be inserted by minimally invasive surgical procedures It would be desirable to provide an apparatus in the art that restores the height of the device.

  According to one embodiment, the expandable implant is configured to restore the bone height of the fractured subject. The expandable implant has a body with a plurality of links connected to form at least one annular row. The links form opposing first and second sides connected by corresponding first and second ends. The first side portion and the second side portion define a distance between the first side portion and the second side portion when the main body is in the insertion form. When the link is subjected to an expansion force, the body is in the expanded configuration such that the distance between the first side and the second side increases from the first distance to a second distance greater than the first distance. Expand. At least the first link of the plurality of links has a size different from at least the second link of the plurality of links so that the first link extends larger than the second link.

  The foregoing summary, as well as the following detailed description of one embodiment of the present application, will be better understood when read in conjunction with the appended drawings, which illustrate the embodiment by way of example. However, it should be understood that this application is not limited to the arrangements and instrumentalities shown.

It is a perspective view which shows the expandable implant of an insertion form. 1B is an enlarged perspective view showing a part of the expandable implant shown in FIG. 1A. FIG. 1B is a schematic perspective view of a portion of the expandable implant shown in FIG. 1B. FIG. FIG. 2B is a schematic perspective view similar to FIG. 2A showing the expanded configuration of the implant. FIG. 2B is a schematic perspective view similar to FIG. 2A showing an implant configured in accordance with an alternative embodiment. FIG. 3B is a schematic perspective view similar to FIG. 3A showing the expanded configuration of the implant. 3B is a perspective view of the first link of the implant shown in FIG. 3A. FIG. 3B is a perspective view of the second link of the implant shown in FIG. 3A. FIG. 1 is an exploded perspective view of an implant system configured in accordance with one embodiment. FIG. FIG. 4B is a partial perspective view of the implant system shown in FIG. 4A. FIG. 4B is a cross-sectional view of the implant system shown in FIG. 4B. FIG. 4D is a partial perspective view of an expandable implant assembly included in the implant system shown in FIG. 4C. FIG. 2 is a schematic plan view of a pair of opening assemblies inserted into a vertebra, each including a cannula and an opening device housed in the cannula. FIG. 5B is a schematic view of the opening assembly shown in FIG. 5A, showing the opening device in an aligned and abutting position. FIG. 5B is a perspective view of one of the cannulas shown in FIG. 5A. FIG. 5B is a perspective view of a portion of one of the opening devices shown in FIG. 5A. FIG. 5D is a perspective view of an opening assembly having the opening device shown in FIG. 5D inserted into the cannula shown in FIG. 5C. FIG. 6 is a perspective view of an opening assembly and a cutting device inserted into a target vertebral body. FIG. 6B is an enlarged perspective view of the cutting device shown in FIG. 6A, showing the cutting device in an insertion form with cutting teeth retracted. It is the expansion perspective view of the cutting device shown in Drawing 6B, and shows the cutting device of the cutting form which extended cutting teeth. FIG. 6B is a perspective view similar to FIG. 6A, showing a state in which the opening device has been removed. FIG. 6 is a perspective view of a portion of a cutting device configured in accordance with an alternative embodiment. FIG. 6 is a perspective view of a portion of a cutting device configured in accordance with another alternative embodiment. 1 is a schematic view of an opening device inserted into a vertebra after an osteotomy has been performed. FIG. FIG. 3 is a schematic view of an implant assembly installed in a target vertebra in an insertion configuration. FIG. 7B is a side view of the implant assembly shown in FIG. 7B containing a filler. FIG. 7B is a schematic view of the installed implant assembly shown in FIG. 7B, showing the expanded configuration of the implant assembly. 1 is a schematic view of a pair of implant systems installed in a target vertebral body in an expanded configuration. FIG. FIG. 2 is a schematic view of an opening device and a clamp, showing a guidewire inserted through the opening device and engaged at one end by the clamp. FIG. 8B is a schematic view similar to FIG. 8A showing an expandable implant assembly installed over a guidewire. It is a perspective view of a normal tibial plateau. FIG. 9B is a front view of the normal tibial plateau shown in FIG. 9A. FIG. 9B is a perspective view similar to FIG. 9A showing a fractured tibial plateau. 9D is a front view of the fractured tibial plateau shown in FIG. 9C. FIG. 9D is a front view of the fractured tibial plateau shown in FIG. 9D showing the expandable implant assembly implanted in the fracture site in an insertion configuration. FIG. FIG. 9E is a front view of the fractured tibial plateau shown in FIG. 9E, showing the tibial plateau using the expanded implant assembly to restore the normal height of the tibial plateau.

  Referring initially to FIGS. 1A and 1B, the expandable augmentation implant 20 is configured to be inserted into a target bone, such as a vertebral body. According to one aspect of the present disclosure, the expandable insert 20 is configured to be inserted into a vertebral body of a trauma vertebra, such as a spinal compression fracture (“VCF”). As will be appreciated from the description below, the implant 20 is configured to be implanted by a minimally invasive surgical procedure, such as, for example, via one or more cannulas, preformed holes, or percutaneously. . After implantation, the expandable implant 20 is configured to reduce and stabilize the subject's bone to restore structural integrity and reduce or eliminate painful micromotion.

  Thus, the implant 20 is in a first insertion configuration of a corresponding first insertion size configured to allow the implant 20 to be inserted into the internal volume of the subject's bone. After being inserted into the subject's bone, the expandable implant can be expanded from an insertion configuration to a second expansion configuration of a corresponding second expansion size that is larger than the insertion size. In the expanded configuration, the implant 20 generally creates a cavity in the internal volume of the target bone, restores and stabilizes the height of the target bone, and occupies or expands a portion of the internal volume of the target bone. Is possible.

  The implant 20 is shown to include a generally annular implant body 22 disposed about a central axis 24 extending in the direction of axis A. The implant 20 can be made from a polymeric material with directed fibers and can be coated with one or more antibiotic preparations, if necessary, to control infection. According to one embodiment, the implant 20 is made from Finox® material. The implant 20 can be further coated with an osteoconductive layer such as sprayed hydroxyapatite or other Ca and P composites. The implant 20 can be manufactured using a selective laser melting or sintering method to uniformly change the shape of the bar.

  The implant body 22 includes an inner surface 22a that forms an inner cavity 23 and an outer surface 22b on the opposite side. The implant body 22 has a plurality of linked links 26. Each link portion 26 includes an opposing flexible first side portion 28 and a second side portion 30, respectively, and is connected between the side portion 28 and the side portion 30, and the opposing flexible first end portion 32 and A second end 34 is provided. According to the illustrated embodiment, the ends 32 and 34 are curved and define a radius of curvature, but it should be understood that the ends can form any suitable shape as desired. Similarly, side 28 and side 30 are generally straight and parallel along the axial direction when implant 20 is in the insertion configuration, but side 28 and side 30 may be any It should be understood that suitable shapes and spatial relationships can be defined.

  According to the illustrated embodiment, the links 26 are arranged in at least one, for example a plurality of columns 27 and at least one, for example a plurality of rows 29. The column 27 extends along a column direction that coincides with the axial direction of the illustrated embodiment. The rows 29 extend along a row direction that is a circumferential direction that forms an annular portion in the illustrated embodiment. The ends of the links 26 are integrally or directly connected to each other along the row direction as shown in the figure. Alternatively, the links 26 may be indirectly connected to each other via a connecting member. Please understand that this is possible. The sides of the links 26 are indirectly connected to each other via corresponding circumferential arms 36, but it is understood that the sides of the links 26 can also be directly connected to each other. I want to be. Thus, it can be said that the links 26 are connected to each other directly or indirectly along the row and column directions forming the column 27 and the row 29, respectively.

  According to one embodiment, the sides 28 and 30 extend in the axial direction. That is, it extends along a direction having an axial component. In other words, the side portions 28 and 30 extend along a direction that is angularly offset with respect to the radial direction R that extends along a direction orthogonal to the central axis 24. Accordingly, as will be understood from the following description, the ends 32 and 34 are configured to expand when a radially outward force is applied to the implant body 22. For example, as described in more detail below, an expansion device 58, such as an expandable bladder (see FIGS. 4A-4D), can be disposed within the implant body 22 and the expansion material expands the bladder. As a result, it can be injected into the bladder to expand the implant body 22.

  According to the embodiment shown in FIGS. 1A and 1B, when the implant 20 is in the insertion configuration, each predetermined link defines a length L1 extending between the opposing ends 32,34. Also, when the implant 20 is in the insertion configuration, the side portions 28 and 30 extend substantially parallel to each other and are separated from each other by a first or insertion distance D1 extending circumferentially according to the illustrated embodiment. In other words, the side portions 28 and 30 are separated by a first distance D1 at selected positions along the length of the side portions 28 and 30. Accordingly, the perimeter of the implant body 22 is at least partially defined by the first distance D1. When the implant 20 is in the insertion configuration, the implant body 22 defines a first cross-sectional distance CS1, which can be a diameter, for example when the implant forms a cylindrical surface as shown. The first cross-sectional distance CS1, and thus the first distance D1, forms a first insertion size implant 20 configured to allow the implant 20 to be inserted into the internal volume of the subject's bone.

  The expandable implant 20 is configured to expand from the insertion configuration shown in FIGS. 1A and 1B to the expansion configuration shown in FIGS. 2A and 2B. As shown in FIG. 2A, since each link 26 is configured substantially the same, the initial length L1 and the distance D1 between other links 26 are defined. A sufficient amount of thermosetting bone filler in the interior volume 23 of the implant 20 so that the thermosetting bone filler fills the cavity 23 and applies a radially outward expansion force F to the link 26. Upon insertion, the implant 20 can be expanded from the inserted configuration to the expanded configuration. The bone filler can take the form of, for example, bone fragments, allograft bone, or biocompatible bone cement. An example of a suitable biocompatible bone cement is self-hardening (eg, self-hardening) polymethylmethacrylate (PMMA), but the bone filler can be selected from any suitable bone filler material as desired. Please understand that.

  Referring to FIG. 2B, the link 26 expands when a radially outwardly expanding force F is applied to the inner surface of the link body 22 and particularly to the link 26. For example, the initial distance extending between at least one and the side portions 28 and 30 of all the links 26 from the first insertion distance D1 to the second extension distance D2 longer than the first insertion distance D1. To increase. At the same time, the length of at least one and at most all the links 26 is reduced from the first length L1 to the second extended length L2 which is shorter than the first insertion length L1. Assuming that the expansion force F is evenly distributed about the implant body 22, the similarly configured link 26 expands substantially uniformly, and the implant body 22 is more than the first insertion cross-sectional distance or diameter CS1. Expand to a larger second expanded cross-sectional distance or diameter CS2.

  As described above with reference to FIGS. 2A and 2B, all of the links 26 may be configured substantially the same, but at least one, for example, the first plurality of links 26 may have at least one, for example, the second plurality of links. It is understood that the link 26 can be configured differently. For example, referring now to FIG. 3A, the expandable implant 20 is illustrated in its inserted configuration, according to an alternative embodiment. As shown, the implant 20 has a first plurality of links 26a (see also FIG. 3C) and a second plurality of links 26b (see also FIG. 3D). The link 26a and the link 26b can be arranged at an interval in the circumferential direction so that the link 26a and the link 26b face each other in the circumferential direction. Otherwise, the first selected number of columns 27, in particular adjacent columns 27, may be provided with links 26a, while the second selected number of columns 27, in particular adjacent columns 27, will be provided with links 26b. Can do. Alternatively or additionally, a first selected number of rows 29, in particular adjacent rows 29, may comprise links 26a, while a second selected number of rows 29, in particular adjacent rows 29, may comprise links 26b. As described above, the link 26a and the link 26b can be arranged at an interval in the radial direction.

  According to the illustrated embodiment, the first insertion length L1 of the first plurality of links 26a is longer than the first insertion length L1 of the second plurality of links 26b when the implant 20 is in the insertion configuration, resulting in The distance D1 of the first plurality of links 26a is substantially the same as the distance D1 of the second plurality of links 26b (the distance D1 was considered to be different between the links 26a and 26b as necessary). . Accordingly, it should be understood that the distance D1 of the first plurality of links 26a is configured to extend larger than the distance D1 of the second plurality of links 26b. According to one embodiment, the first plurality of links 26a expand at a greater rate than the second plurality of links 26b when subjected to substantially the same expansion force as the second plurality of links 26b. In this way, the implant 20 can be configured to produce a symmetrical shape under uniform expansion force as shown in FIG. 2B, or the implant 20 can be configured as shown in FIG. 3B. It can be configured to produce an asymmetric shape under uniform expansion force.

  According to one embodiment, the implant 20 is inserted into the subject's bone in its insertion form, so that the link 26 passes through the cannula and the pedicle as described in more detail below. Can be referred to as being in a compressed or collapsed configuration so that it can pass through the opening formed in and into the internal cavity of the subject's vertebral body. According to one embodiment, the implant 20 can follow the curved guide path of the curved guidewire so that the implant 20 can be flexible to follow the curved guide path. However, bending of the implant 20 in place while moving along the guide path can result in plastic deformation to provide the implant with adequate structural stability. For example, expansion of the implant 20 by injection of a bone filler causes the structure of the implant 20 to go beyond the elastic phase of the material and thus cause plastic deformation of the implant 20. If the target bone is a vertebral body, the plastic deformation of the implant allows the implant 20 to provide enhancement to the anterior surface of the vertebral body.

  When the implant 20 includes the first plurality of links 26a and the second plurality of links 26b, the hook law is that the implant body 22 assumes an asymmetric or curved shape when the implant body 22 is elastically expanded. Show that you can. However, it should be understood that the expansion of the links 26a and 26b occurs beyond the limit of elastic deformation so that the implant body 22 can also be plastically deformed to some extent. The implant is fixed in a fully expanded state by a later injected bone filler.

  Embodiment-Application of Hooke's Law

  Definition:

  ε strain

  σ Tensile strength

  A Cross section of the rod

A _i 0.4mm ²

A _O 0.2mm ²

  l Length of bar

l _i 8mm

l _o 10mm

  E Modulus of elasticity Finox (registered trademark): 203-400 MPa

  Elongation: Δl = ε · l

  However, the strain is: ε = σ / E

  Therefore: Δl = σ · l / E

"i" indicates the region of the implant body 22 having a second plurality of links 26b (which may be disposed at the inner end in the circumferential direction of the implant body 22), while "o" indicates the first plurality of links 26a (implant body FIG. 2 illustrates an area of the implant body 22 having a circumferentially extending outer edge (assuming that the expansion is subject to a substantially uniform expansion force (or tension)). The resulting tensile strength of the second plurality of links 26b and the first plurality of links 26a is as follows:
σ _i = F / A _i = 120 N / 0.4 mm ² = 300 [N / mm ² ]
σ _o = F / A _o = 120 N / 0.2 mm ² = 600 [N / mm ² ]

The resulting stretches of the second plurality of links 26b and the first plurality of links 26a are as follows:
Δl _i = σ _i · l _i / E = 300 MPa · 8 mm / 203′400 MPa = 0.011 mm
Δl _o = σ _o · l _o / E = 600 MPa · 10 mm / 203′400 MPa = 0.030 mm

  Based on this analysis, the implant 20 is expanded significantly in the area of the link 26a than in the area of the link 26b (approximately 3 times in the example identified above). As a result, since the extension of the second plurality of links 26b is smaller than that of the first plurality of links 26a, the implant 20 bends when expanded. It should be understood that the numbers in the above example are merely assumptions used to illustrate the bending effect based on the different link dimensions of the expansion implant 20 and do not represent actual test data.

  With reference now to FIGS. 4A-4D, it is envisioned that the implant system 50 may have the implant 20 with a system device that facilitates insertion and expansion of the implant 20 into the bone of interest. For example, the system 50 includes an opening assembly 52 that includes a cannulated body 62a, an opening device 62b (see FIG. 5A) housed within the cannulated body 62a, and an aiming device that supports the opening assembly 52. 54 (see FIG. 5A), a cutting device 56 (see FIGS. 6A-6F) configured to perform osteotomy, and an implant 20 and an insertion configuration configured to provide bone augmentation There may be an expandable implant assembly 25 with an expansion device 58 configured to repeat the implant 20 in configuration. Further, the system 50 can include a bone filler device configured to be inserted into the dilator 58 under pressure to expand the dilator 58 relative to the implant 20. The system 50 may also include a guide 60 that forms a guide path for the implant 20 into the bone of interest. Also, the system 50 can include an osteotomy cutting device 56 that can be provided on the guide 60 or can be provided separately from the guide 60 as shown in FIGS. 6A-6F. I want you to understand.

  Referring also to FIGS. 5A-5D, the opening assembly 52 includes a cannulated elongate body 62a that forms a proximal end 64a and an opposing distal end 66a, and a distance from the proximal end 64a along the direction of extension. A cannula 68a extending through the body 62a into which the cannula is inserted up to the distal end 66a. The cannulated body 62a is generally straight and is coupled to the handle 67a at the proximal end 64a. In addition, the opening assembly 52 includes a flexible or elastic elongated opening device 62b sized to be received in the cannula 68a. The opening device 62b may include a proximal end 64b and an opposing distal end 66b, and a cannula 68b extending through the opening device 62b from the proximal end 64b to the distal end 66b. Opening device 62b is coupled to handle 67b at proximal end 64b. Cannulas 68a and 68b can extend through respective handles 67a and 68b. The distal end 66b may comprise an opening member configured to cut the cutting blade 65 or the bone of interest. The opening device 62b is curved at a location proximate to the distal end 66b, such that the distal end 66b is disposed within the cannula 68a in a linear configuration but is curved when disposed outside the cannula 68a; More flexible. The opening device 62b can be formed from any suitable elastic bending material, such as Nitinol (ie, nickel-titanium alloy). Accordingly, the opening device 62b may be formed to correspond to the size and shape of the target bone, such as the target vertebra 70. The system 50 may have a pair of symmetrically formed aperture assemblies 52 that can be inserted into the vertebra 70 of interest.

  During surgery, the opening device 62b is inserted into the proximal end 64a of the cannulated body 62a such that the curved portion of the opening device 62b extends from the distal end 66a of the cannulated body 62a. be able to. For illustration purposes, FIG. 5A shows one of the cannulated bodies 62a containing the cutting device 62b, while the other cannulated body 62a does not hold the cutting device. FIG. 6B shows a pair of opening assemblies 52 having a cannulated body 62 and a cutting device 62b disposed within the cannula of each cannulated body 62. FIG. According to one embodiment, the opening device 62b can be inserted into the vertebra 70 according to a pedicle penetration approach. The puncture incision can be used to access the pedicle 72 of the subject's vertebra 70 under intraoperative radiological observation. Both pedicles 72 of the targeted vertebral body 74 push the distal cutting end 65 into the respective pedicle 72 so that the opening device 62b penetrates the cortical bone of the corresponding pedicle 72. Is opened. As shown in FIG. 5A, the opening device 62b can then be deformed along the axis of the pedicle to penetrate the cancellous bone in the vertebral body 74 and pierce the arcuate channel. The curved shape of the opening device 62b aligns and abuts the respective distal ends 66b as desired.

  The system 50 further includes a body 78 and a sighting device 54 having a pair of spaced openings 80 extending through the body 78 sized to receive a corresponding pair of cannulated bodies 62a. be able to. The openings 80 are aligned and spaced to be configured to allow intraoperative communication by the distal end 66b of the corresponding opening device 62b to facilitate insertion of the expandable implant 20. . According to the illustrated embodiment, as shown in FIG. 5B, the distal ends 66b are aligned and abut each other when inserted into the vertebral body 74.

  Referring also to FIG. 6A, after the opening device 52 is in place, the osteotomy cutting device 56 passes through one cannula 68b of the opening device 62b at the proximal end 64b and distant from the opening device 62b. It can be inserted through the distal end 66b, into the distal end 66b of the adjacent opening device 62b, and through the proximal end 64b of the adjacent opening device 62b. As shown in FIGS. 6B and 6C, the cutting device 56 forms a body 76 having a pair of end portions 79 at the counter electrode, and the cutting portion 81 is disposed at the center between the end portions 79 at the counter electrode. Yes. Each of these end portions 79 can be screwed and connected to the cutting portion 81 at each joint 77. The body 76 can be sized to fit within the opening device 62b and is positioned within the cannulated body 62a. The cutting device body 76 can be manufactured from a flexible wire material so that the cutting device 56 can move through the curved cannula 68. The body 76 is longer than the pair of aperture assemblies 52 such that when the body 76 is disposed within the cannula 68, the end 79 at the counter electrode extends out from the proximal end 64 of the aperture assembly 52. Can.

  The cutting portion 81 can have a plurality of cutting members in the form of teeth 82 projecting from the body 76 so as to be retractable. The cutting device 56 can further include a protective sleeve 84 that fits over the teeth 82. The sleeve 84 has a sleeve main body 85 and a plurality of openings 86 that penetrate the sleeve main body 85. The opening 86 is sized to accommodate each tooth 82. The sleeve 84 is positioned in a first guard position (FIG. 6B) relative to the teeth 82 so that the body 85 and the teeth 82 are aligned to protect the teeth 82 from cutting adjacent structures. Can do. The sleeve 84 can be moved to a second cutting position relative to the tooth 82 (FIG. 6C) such that the opening 86 and the tooth 82 are aligned. The teeth 82 can be deflected to extend out of the cutting body 76 through the openings 86 when the openings 86 are aligned with the teeth 82, thereby cutting the adjacent structure of the teeth 82. Configured to do.

  During the operation, the cutting body 76 is inserted via one opening device 62b together with one end 79 attached to the cutting part via a joint 77. This cut is inserted into the respective proximal end 64b, passes through the distal end 66b, and is inserted into the distal end 66b of the adjacent opening device 62b. Next, the opposite end 79 is inserted into the proximal end 64 b of the adjacent opening device 62 b and inserted into the opening device 62 b until it contacts the joint 77. At that position, the end 79 at the counter electrode is rotated so that this end 79 is screwed into the cut 81. Thus, the end 79 at the counter electrode of the cutting device 56 extends out from the proximal end 64a of the opening device 62b.

  After the cutting device 56 is in place, the opening device 62b can be removed while the cutting device 56 is in place, as shown in FIG. 6D. Thereafter, the sleeve 84 can be moved to the cutting position. For example, the sleeve 84 can be manually moved to the cutting position, or the actuator can extend out from one or both proximal ends 64b of the opening device 62b. It is possible to extend to one or both of the ends 79 at the counter electrode and this sleeve 84 can be moved to repeat to the cutting position. With the removed opening device 62b and the cutting teeth 82 extending through the opening 86, the end 79 at the opposite electrode can be moved back and forth, thereby causing the cutting teeth 82 to cut the cortical bone and cut the osteotomy. Perform the technique. As shown in FIG. 6D, the handle 83 can be attached to an end 79 at the counter electrode in the cutting device body 76 to assist the cutting operation. After the cortical bone has been cut, the sleeve 84 can return to its protected position. For example, the teeth 82 can have an inclined surface that is formed along the sleeve body 85 and retracts the teeth 82 as the sleeve body 85 moves to the protected position.

  Referring now to FIG. 6E, the cutting device 56 can be configured without the sleeve 84 according to a variation of the embodiment. Cutting member 82 is illustrated as a diamond-shaped tooth configured to scrape cortical bone as cutting device 56 is repeatedly moved back and forth. As shown in FIG. 6F, the cutting member 82 can be configured as an opening that penetrates the cutting body in a direction that defines a negative cutting angle.

  Referring now to FIG. 7A, after the osteotomy has been completed, the opening device 62b is again inserted into the cannula body 62a and into the subject's vertebra 70 in the manner described above so that the distal end 66b is at the fracture site. Arranged close to each other and abutting each other. As shown in FIG. 7B, after the opening device 52 is inserted into the vertebra 70, the expandable implant assembly 25 is inserted into the opening device 62 and subsequently expanded, as will now be described.

  With particular reference to FIGS. 4A-4D and FIGS. 7A-7C, the expansion device 58 is a rubber that forms an expandable bladder or other flexible member configured to close the internal cavity 23 of the implant body 22. It can have an expansion body 96 that can be made from any suitable material such as plastic or plastic. The expansion device 58 extends through the expansion body 96 and forms a lumen 97 sized to receive the guide wire 60. The body 96 is closed at the distal end 105 and open at the proximal end 107. As shown in FIG. 4D, the expansion implant 20 is positioned on the expansion device 58 to form the expandable implant assembly 25. The outer diameter of the expansion assembly 25, defined by the outer diameter of the expandable implant 20, is sized to fit within the opening device 62b so that the expansion assembly 25 can be driven through the opening device 62b. It has become. The lumen 97 houses the guide wire 60 so that the guide wire 60 can be placed in the opening device 62b, thereby allowing the implant assembly 25 to be placed in the subject vertebra 74. . In this regard, the cannula body 62a, the opening device 62b, and the guide wire 60, both alone and in combination, form a guide path for the expandable implant assembly 25 having the implant 20 and the expander 58, or at least It should be understood that it forms partly.

  As shown in FIG. 7A, the opening device 62b is moved through the cannula body 62b such that its distal ends 66b abut each other in the manner described above. Next, as shown in FIG. 7B, the expansion assembly 25 is opened so that the expansion assembly 25 is positioned between the bone piece created during osteotomy and the remaining integral bone portion. The device 62b is moved into the vertebral body and subsequently the opening device 62b is removed. The dilator body 96 is sufficiently long so that when the implant 20 is placed in the vertebral body 74 of interest, the proximal end 107 extends into the opening device 62b and optionally extends out of the proximal end 64b. It is possible to be. The expansion device body 96 can be divided into a plurality of body dividers 98 that are hinged to each other at each joint 103 to move about the joint relative to each other. Thus, as shown in FIG. 7C, the dilator main body 96 can bend between adjacent splits 98 when the dilator main body 96 moves into the vertebral body 74. Thus, the implant 20 can be formed as at least one link 102, such as a plurality of separate individual links 102 spaced along the tandem direction. Each link 102 may form at least one column of links 26 and at least one row of links 26 as described above. The link 102 can be mounted on each body divider 98 in a substantially flat insertion configuration until the expansion assembly 25 is installed in the vertebral body, at which point, such as cement or similar solid filler. 7C and 7D, the filling material 59 is injected into the lumen 97 through the proximal end 107 of the dilator 58 under positive pressure using, for example, a piston pump or syringe. The positive pressure generated by the filler 59 causes the body 96 to expand for each link 102, thereby expanding the link 102 in the manner described above.

  In this manner, the expandable implant 20 can be expanded from the inserted configuration to the expanded configuration by injecting bone filler into the internal cavity of the expandable implant using any suitable injection device. Expansion of the expandable implant 20 compresses the surrounding cancellous bone tissue in the internal volume of the subject's bone, thereby forming a cavity. Also, expansion of the expandable implant 20 preferably repositions and stabilizes the surrounding bone and / or bone tissue, thereby anatomically placing the fractured bone until the injected bone filler has hardened. Restore.

  It can be said that the filler is injected into the cavity 97 of the expansion implant 20 because the filler is injected into the lumen 97 of the expansion body, and the lumen 97 is disposed in the internal cavity 23 of the expansion implant 20. Thus, the implant 20 is expandable substantially uniformly, for example when all the links 26 are made substantially identical, or, for example, the first plurality of links 26 is different from the second plurality of links 26. It can bend as the implant 20 expands when it has expansion characteristics, such as different sizes (eg, a greater length that results in greater expansion). The implant 20 is secured in an expanded configuration when a bone filler such as cement is solidified and / or hardened.

  The dilator 58 has a weakened constriction 109 disposed between the proximal end 107 and the link 102. For example, the constriction 109 can be configured to allow material to be removed, thereby separating it from the remainder of the dilator body 96. After the bone filler material 59 has solidified and / or hardened, a rotational force can be applied to the proximal end 107 of the dilator body 96, thereby breaking the body 96 at the narrowed portion 109, resulting in the link 102. The proximally disposed cutting portion of the body 96 can be removed along with the bone filler disposed within the lumen 97 of the removed portion. Alternatively, the body 96 can be terminated in the immediate vicinity of the link 102 such that the entire body 96 is inserted into the vertebral body 74 and the syringe injects bone filler into the lumen 97. Therefore, it is possible to penetrate the main body 96.

  Thus, during use, the cortical surface of the subject's bone is opened using, for example, a cone or other cortical opener. After osteotomy has been performed, the expandable implant 20 can be inserted in a straight configuration. Expansion of the implant 20 allows the position of the bone interface or other surface to be reduced or even diverted. Due to the expansion of the implant 20, the implant is bent based on its specific design characteristics. In this way, the implant 20 allows for more sophisticated fragment reduction. Further, it should be understood that the expansion implant 20 can be inserted into the subject's bone via a minimally invasive device or system.

  According to an alternative embodiment, FIG. 7E shows that the implant system 50 can have a pair of implant assemblies 25, each implant assembly 25 being configured as described above, although the subject vertebral body The length is shortened so as to extend to substantially the middle part of 74. Thus, one implant assembly 25 can be placed on the first side of the vertebral body 75 and the other implant assembly 25 can be placed on the second side opposite to the vertebral body 75. According to one embodiment, the first side surface and the second side surface include an intermediate surface and a side surface. Thereafter, each implant assembly 25 can be expanded independently of each other by injecting bone filler 59 in the manner described above. Thus, the height of each implant 20 can be adjusted independently, thereby adjusting the portions of the target vertebra 74 independent of each other.

  Referring now to FIGS. 8A and 8B, the system 50 can be configured in accordance with an alternative embodiment whereby the implant 20 is installed and expanded in the vertebral body 74 after osteotomy has been performed. The In particular, the aiming device 54 can include an arm 87 coupled to the aiming device body 78 via a knob 91. The knob 91 extends through an elongated slot 89 extending through the arm 87 and is further screwed into the aiming device body 78. Accordingly, the arm 87 is movable with respect to the aiming device main body 78 when the knob 91 is loose, and can be fixed with respect to the main body 78 when the knob is tightened. The arm 87 can abut the subject's vertebra 70 at, for example, the spinous process 71, thereby allowing the cannula to be in the desired position and orientation, eg, in line with the retainer for the opening device 52 and the pedicle 72, for example. It constitutes a positioner for installing the main body 62a.

  The opening assembly 52 includes a straight cannula body 62a, which is provided as a wire 61 that is moved through the pedicle 72 as described above with respect to the opening device 62b of FIGS. 7A-7E. The wire 61 differs from the opening device 62b mainly in that the wire 61 is not inserted into the cannula. After the wire 61 is moved through the vertebral body 74 of interest, the distal end 66b of the wire 61 can be engaged by a clamp 92 that extends through the adjacent cannula body 62a. The implant system 50 further includes a pair of handles 94 that are coupled to the guidewire 61 at a location proximate to the handle 67a.

  Thus, the opening wire 61 is inserted through one of the cannula bodies 62a and pushed through the cancellous bone of the vertebral body 74. A clamp 92 is inserted through the cannula 68 of the other opening device 52 and a knob 93 coupled to the clamp 92 causes the clamp 92 to engage the wire 61 so that the clamp 92 holds the wire therein. Can be moved to. The knob 93 can then be pulled, thereby pulling the wire 61 through the adjacent cannula body 62b until the distal end of the wire 61 extends through the proximal end of the cannula body 62b or the handle 67a. It should be understood that as the wire 61 is moved through the cannula body 62a, the wire 61 can bend so as to extend around the vertebral body 74 to the clamp 92. In this regard, the wire can be made from any suitable elastic bending material such as nitinol (ie, a nickel-titanium alloy). The guidewire 61 can be provided with one or more cutting teeth at the cutting portion 111 disposed on the vertebral body 74 after the guidewire 61 is pulled by the clamp 92.

  As a result, by repetitively moving the wire 61 back and forth with respect to the vertebral body 74, the cortical bone can be cut with the wire in order to perform osteotomy. Thereafter, the wire 61 can be removed. As a variant, one end 79 of a cutting device 56 of the type described above can be attached to one end of the wire 61, the wire 61 having the cutting part 81 arranged on the vertebral body 74 as described above. Can be pulled through the cannula body 62a to guide the cutting device 56 into the cannula body 62a.

  After the osteotomy is completed, the augmentation implant 20 is inserted between the bone fragment created during the osteotomy and the integral part of the remaining vertebral body 74 and then as described above with respect to FIGS. 7A-7E. Can be extended.

  Certain embodiments, in combination with injected bone filler (e.g., bone cement), expand the internal volume of the subject's bone, restore bone height, and fill cavities formed in the bone; And / or described with respect to expandable implants (eg, stents) that are used to stabilize, assist and / or augment bone. Although the expansion implant 20 has been described as being used in a subject's bones shown as the spine (eg, the lumbar, thorax, or cervical region), those skilled in the art will recognize that the implant 20 is not a part of the body. Used to augment bones of alternative subjects, including long bones such as proximal humerus and proximal tibia, or bones of the hand, face, feet, limbs, skull, or almost any human body It should be understood that it may be understood that

  For example, referring to FIGS. 9A-9E, the subject's bone is a tibial plateau 99 whose natural state is shown in FIGS. 9A and 9B. FIGS. 9C and 9D show the tibial plateau 99 fractured to produce a tibial fracture piece 100 that is separated from the remaining integral bone portion 101 of the tibial plateau 99. Referring to FIG. 9E, after the fracture piece 100 is moved and reduced, the implant assembly 25 is inserted between the integral bone portion 101 and the fracture piece 100 in a straight line configuration. In this regard, it should be understood that a fracture piece may be generated during osteotomy or by a fracture, for example due to an injury. The bone filler is then inserted into the lumen 97 extending through the expansion body 96 as described above. When the implant 20 expands and curves, the fracture piece is reduced as shown in FIG. 9F. The implant 20 is fixed in an expanded configuration when a bone filler such as cement hardens and / or hardens so that the height of the fractured tibial plateau is restored to its normal height.

  It will be appreciated by those skilled in the art that modifications may be made to the above-described embodiments without departing from the broad inventive concepts herein. Accordingly, it is to be understood that the invention is not limited to the specific embodiments disclosed, and is intended to encompass modifications within the spirit and scope of the invention as defined by the specification.

Claims (26)

An expandable implant configured to restore the bone height of a fractured subject,
An elongated body along the central axis, e Bei the concatenated plurality of links to form at least one annular row of links that are arranged in a plurality of columns, each annular row extends along the row direction The links form opposing first and second sides connected by corresponding first and second ends, and the first and second sides are linked to the links. The distance between the first side and the second side is defined so that the distance increases from the first distance to the second distance when receiving an expansion force that expands the main body from the insertion form to the expansion form. The second distance is longer than the first distance and has the body.
The plurality of links include at least a first link arranged in the first column of the column and a second link arranged in the second column of the column, and the first column and the second column are Each having a single link thickness along the row direction, the first link extending at least a second of the plurality of links such that the expansion force causes the first link to expand more than the second link. The first and second rows define the same number of links , so that when the expansion force is applied, the body is asymmetric from the insertion configuration to the expansion configuration. Expandable implant wherein the body is curved so that the central axis is curved when the body is in an expanded configuration .   The expandable implant of claim 1, wherein the links are directly connected to each other.   The expandable implant according to claim 1, wherein the links are indirectly connected to each other.   The expandable implant according to claim 1, wherein the body is substantially cylindrical when the body is in an insertion configuration.   The expandable implant of claim 1, wherein the body is asymmetrical when the body is in an expanded configuration.   6. The expandable implant of claim 5, wherein the body is curved when the body is in an expanded configuration.   The expandable implant of claim 1, wherein the first side and the second side are substantially straight.   The expandable implant according to claim 1, wherein the first side and the second side are substantially parallel to each other.   The expandable implant according to claim 1, wherein the end portion is curved between the side portions.   The expandable implant according to claim 1, wherein the distance is a circumferential distance.   The body has a plurality of separate individual links configured to be interconnected via an expansion device configured to receive a filler to apply an expansion force to the implant body. The expandable implant according to claim 1.   The expandable implant according to claim 1, wherein the implant is a spinal implant. An expandable implant assembly configured to insert an implant into a target bone,
An implant body forming an internal cavity, the implant body comprising a plurality of links interconnected to form at least one annular row extending along the row direction, the row being arranged in the column direction Arranged to form a plurality of columns extending along each column, wherein each column forms a first end and a second end on opposite sides along the column direction, and the link is at least a first column of columns. And a plurality of second links arranged in the second row of the columns, each first link defining a first length along the column direction, the second link defining a second length along the column direction, the second length is shorter than the first length, thus the first link have different expansion characteristics than the second link, the each of the plurality of second link along the column direction From first end portion to the second end portion, and the implant body to be attached to each other and adjacent second link of the plurality of second link,
An expandable bladder sized to be disposed within the internal cavity, wherein the bladder applies an expansion force to the bladder, thereby expanding the first link to a greater extent than the second link. An expandable implant assembly having a bladder configured to receive an expansion material so as to apply an expansion force to the implant body. The bladder is, according to claim 13 comprising a plurality of divided portions, which are mutually hingedly connected around each joint, and a the implant body having a plurality of links spaced the plurality of divided portions on Expandable implant assembly. 14. The expandable implant assembly according to claim 13 , wherein the target bone is a vertebral body. 14. The expandable implant assembly according to claim 13, wherein the implant body is curved when the implant body is in an expanded configuration. An implant system configured to insert an implant into a fracture site of a subject's bone,
Has an expandable implant body circumferentially expanded configuration from an insertion configuration, the implant body forms the shape of the interior cavity, to form at least one annular row of links that are arranged in a plurality of columns A plurality of connected links, each column extending along the column direction, forming a first end and a second end on opposite sides along the column direction, and each annular row along the row direction At least a first link of the links such that when the expansion force is applied to the implant body from an expansion material, the first link expands larger than the second link. The at least one first link is arranged in a first column, and the at least one second link is arranged in a second column that faces the first column in the circumferential direction. Is, the addition of the expansion force to the implant body, said body is curved in a direction toward the second column from the first column,
The implant body has (1) the first column and the second column each have a single link thickness along the row direction and include the same number of links, or (2) the first column And the second column is configured to include a plurality of links attached to each other from the first end to the second end along the column direction,
Furthermore, it has an opening device with a cutting blade configured to cut the target bone, the opening device forming a cannula with a proximal end and an opposite distal end, the cannula being An implant system that forms a guide path configured to receive the implant body to guide the implant body to the fracture site when the distal end is positioned proximate to the fracture site.   Further, an expandable bladder sized to be disposed within the internal cavity so that the expansion material applies an expansion force to the bladder, thereby expanding the first link more than the second link. 18. The implant system of claim 17, further comprising a bladder configured to form a lumen configured to receive an expansion material so as to apply an expansion force to the implant body.   19. The implant system of claim 18, further comprising a cutting device configured to perform osteotomy of the target bone so as to separate bone fragments from the remaining bone portion.   The cutting device according to claim 19, comprising a plurality of teeth, and a protective sleeve configured on the premise of a first position where the teeth are covered and a second position where the teeth extend through the protective sleeve. Implant system.   20. An implant system according to claim 19, wherein the cutting device comprises a guide wire sized to be received in the cannula. The expandable implant assembly according to claim 13 , wherein the second links are directly attached to each other along a tandem direction. 14. The expandable implant of claim 13 , wherein the body comprises a plurality of arms attached between adjacent second links along a tandem direction such that adjacent second links are indirectly attached to each other. Assembly.   The expandable implant according to claim 1, wherein the first link and the second link are arranged in the same row.   The expandable implant according to claim 1, wherein the at least one annular row is a first row of a plurality of rows, and the first link and the second link are arranged in different rows.   The implant body includes: (1) the first column and the second column each have a single link thickness along the row direction and include the same number of links; and (2) the first column 18. The implant system of claim 17, wherein the second column and the second column are each configured to include a plurality of links attached to each other from the first end to the second end along the column direction.

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